The projects submitted involve development of radiologic diagnostic methods, development of equipment and technology, the rationale for development of these new methods, as well as investigations of physiologic processes made possible by the development of these methods and the multidisciplinary approach toward implementation. Cooperation between many investigators of different backgrounds and interests will enhance greater efficiency and economy, as well as assure progress. Specific description of the projects is presented. BIBLIOGRAPHIC REFERENCES: Swann, S., Kaufman, L., Price, D.C., Guesry, P., Orloff, S., Wilson, C.J. and Huberty, J.P., Fluorescent Excitation Analysis for In-Vitro Test. J. Nuc. Med. Tech. 3: 159, 1975. Kaufman, L., Clinical Uses of Stable Indicators Assayed In-Vitro by Fluorescent Excitation Analysis. (Summary) Amer. Nucl. Soc. Transaction of the Conference on Nuclear Power and Applications in Latin America 21, Sup 2: 62, 1975.